Pneumatic tool.



'To'll whom, ift/may concern:

i'rED STATES PATENT oEFioE., t

HENRY E. LE GENDRE, -oE oREsK1LL,ivEw-.JERSEY, AssieNoR To E.V W. Buss ooM- PANE. 0E ERooKLYN, NEW YORK', A CORPORATION-0F WEST v I'RGtNI'A.'

PNEUiyIArio Toor..

l Application filed' November Specification of Letters Patent.

1 1, 1910. Serial No. 590,625.

Be it known that l. HENRY E. LE GEivDRE, af citizen of the United States,y residingjin Creskill, inthe vcounty of Bergen and State .of New Jersey, have invented certain new and useful Improvements in Pneumatic Tools, of which the following is a specifica tion.

This invention relates to pneumatic tools, and' aims to provide certain improvements therein.

It is particularly directed to pneumatic hammers'. of. the 'type known as 'valveless hammerspthat is to say, those-haminers'in' whichl there-is no separate `valve employed,- the plunger itself act-ing to control the ad'- misson and ehanst of the air.

The principal lobject. of the invention. is to providela tool of this type in which the vplunger is cushioned. upon its downward stroke, and preferably also upon its upward stroke. By this means. crystallization of the plunger and excessive wear on the parts is avoided. This vconstruction also permits the intensity of theA blowto be' modified as desired by the operator, without regulating the flow of air. This feature of iinprovement is particularly valuable when the 'device is used as a stone-cutting tool, since' it enables the operator .to mal-re coars or tine ,cuts by :espere adjustment or the chisel.l

` Y The invention also includes other features of improvement which will be hereinafter more fully described.. l

In the drawings wherein l have illusrited one form of my inventioni-Figure 1 ie-a vertical sectional' view of the instrument, showing the plunger as it is moving downwardly to deliver its blow. Fig. 2 is a similar view showing the plunger as it is 3 is a vertical sec- .ional view with the plunger omitted and illust-rating the casing at right angles to the posi-tions shown in Figs. l and 2. F ig. 4 is a ho-rizontalsectional Aview' of theinstrwl contracted portion b at its tlo'wei" end.t

Within this bore lits the plunger B. Thisl plunger is formed with a .body portion o".

l -of approximately the same diameter as the bore a of the casing and with an extension (Z of approximately the same diameter as the contracted portion b of the bore and into which it projects.I The casing is provided with passagesfor the ladmission of motive-fluid vtothe rear. of the plunger, there sages -e-e with ports f-f, and' with a passage'for the admissionof fluid to the front of the plunger, there preferably 4being but oney of these passages g, with'itsport 71;, and -preferably'formed as an `exten-sion of oneof ing of these .ports are lcontrolled'hyl the plunger Band for this purpose. it is pro'- c and a recess j in its extension el, these recesses being preferably in the form of annular grooves. Plunger B also has longirecess vf in its body portion and i-nto the bore plurality of these. This permits motivefiu-id' to pass tothe rear of the plunger when v@-e-, and motive-fluid is permitted to -pass int-o the front of the bore when recess 7' is opposite port hof passage g. Casing A is also provided with passages for the exhaust of motive-fluid lfrornthe frontv and rear portions of the boret .here 'preferably being a .pluralityof these passages MZ to facilitate rapid exhaustof the motive-fluid. Each lof the passages ZFZ is formed preferably with portsm and n andpassages.

theupper arid lower -portions of .the bore, the opening and closing of these ports being controlled .by the plunger. Passages Z Z communicate with the atmosphere through a port o preferably common to both passages Zand passages Z through a port o passages Z. The upper-end ofl borea is closed by a plug 7J, preferably screw-thread ed intl)A the end of thecasing. This plug is .provided with a passage g for the admis,- sion of motive-fluid, and is -preferably t/hreadedV for the vreception of the threaded 'end of a supply-pipe or hose. Passage g communicates with admission Vpassages e-e through branch passages rf-r 'preferab1y` coiuniwiicetmg with o. groove s Patented Feb. 18,1913."

preferably being a plurality of these pas-- vided with the recess z' in the body portion tudinal passages 7c therein, opening into the` recess c' is opposite ports f--fof passagessimilar 'to' 0', preferably common to both the passagese-e "Theopeningand closin rea-r thereof, there preferably being a -Z with ports m n communicating with formed around the plug. In the upper and lower partsof'bore rifare preferably formed recesses tand u for the expansion of motive-Huid when compressed-by the plunger as it .reciprocates back and forth. Casing A yalso has preferably formed thereon a nose livered.

by which the blow 'ofthe plunger is de- .Operation The sitionillustrated in Fig. l, motive-duid will beadmitted to the l'rear of the plunger to ports n, nand passages Z, Z.

bore.

drive it-downward through inletpassage g. branches 2", r', passages e, e and ports f, f in the casing, and through groove fand passages 7; vin the plunger. Fluid in fro-nt of the, plunger is expelled through exhaust As the plun-A ger moves downward, 'it will cover ports f, f andalso the ports n, n', thus cutting lexpelled throughl ports m, m and passages Z, Z. Rearward movement of the vplunger will cover po'rtlttfand the ports m, m', thus cutting off fluid romin front of the fplunger and c'losingthelexhaust in the rear. Further movement williuncover the portsv l j, andthe plunger will be in position to cycle of operation,

again move downwardv an'dthus repeat the With this, hammer, .tof` secure blows of varying intensities, it is only necessary to varyl the distance between `the end` of t-he plungcr and the end of the tool, which isiny.serted in the socket in' the end of the casing. u, .lVhile I have 'illustrated and described ibutV one embodimentI of the invention, I do not desire'tolbe misunderstood as. limiting myself thereto,'-`as many changes and modiiications may be made thereon without tdeparting vfrom the spirit of the invention.

What I claim is: n

1 A pneumatic tool comprising a casing and a plunger, said casing having a longitudinal bore therein of twordiiferent diameters, adaptedt'o receive said plunger, said plunger having' a body portion adapted to reciprocate in the larger portion of said bore and an extension adapted to reciprocate within the smaller Aportion-'of said bore, ad-

\ missionpassa'ges in communi'cation with the larger and smaller l@irtions-'of lsaid bore. and' exhaust passages'inicominunication with the larger portion of ysaid bore at different lonplunger being. in the po` gitudinal points, the bodv portion of said' plunger controlling the admission of mot-ive fluid to the rear of said plunger, and the exhaust froml the front and rear thereof, and

said ,extension controlling, the' admission of' motive illuid to the front ofsaid plunger.

. .25. A pneumatic'tool'comprising a casing and aplunger, said casing having a lon'- gitudinal bore therein of two different diameters, adapted to receive ,said plunger, said plunger having' a bodyportion adapted to reciprocate in the larger portion of said bore and an extension adapted. to reciprocate within 'the smaller portion of said bore, admission passages in communication with the larger and smaller. portions of said bore,

'and exhaust passages in communicationwith the Ilarger Aportion of said bore at different longitudinal points, the body portion of said plunger having passages therein from its sides toits rear and controllingr the admis sion of mot-ive fluid to the rear of said plunger, andthe exhaust from the,front and rear thereof, and said extension controlling the admission of motive fluid to the` front of said plunger.

3. A pneumatic tool comprisinga casing anda plunger, said casing having a longitudihal bore therein of two different diam- .'eters, adapted to receive said plunger, said plunger having a body portion adapted to reciprocate in the larger portion of said b ore and an extension adapted to reciprocate within the smaller portion ofjsaid bore, ady mission passages in communication with theu larger and smaller portions of said bore, and" laiiger portion of s ad bore at different longitudinal' points, t-l e body port-ion of said plunger controlling the admission of motive exhaust passages in (ymmunicat-ion with the Huid to the rear of said plunger, and the exhaust from thefront land rear thereof, and said extension having i a g-roove therein through which motive fluid is admitted from the smaller to the larger portion df the bore for returning said plunger. u

4t. A pneumatic tool comprising a casing and` a plunger, said' casing havlig a longitudinal bore therein of two different diameters, adapted to receive said plunger, said plunger having a body po'rt-ionl adapted to reciprocate in the larger portion of said bore and an extension adapted to reciprocate withinI the smaller portion of said bore, admission passages in communication with the larger and smallerportions of said bore. and exhaust passages in communication vwith the larger portion of said bore at different -longitudinal points, the body portion of said plunger controlling the admission of motive luid to the rear of said plunger, and the exhaust from the front and rear thereof, and said extension controllingthe admission of Y motive Huid to the front of said plunger and being of suiicient length to remain oonlll borey without being Withdrawn throughout reciprocations of the plunger.

5. A pneumatic tool comprising a easing and a plunger, said casing having a longitudinal bore therein of two different dialneters, adapted to receive said plunger, said plunger having a body portion adapted to reciprocate in the larger port-ion of said bore and an extension adapted to reciprocate Within the smaller portion of said bore, admission passages in communication with the larger and smaller portions of said bore, and exhaust passages in communication with the larger portionof. said bore at different longitudinal points, thebody portion 0;( said plunger oontrolllng the admission of motive fluid to the rear of said plunger, and the exhaus fror the frontand rear thereof, and sai exi 'ion controlling the admission of mo' 2U, tive duid to the front of said plunger and cutting 0H admitted motive fluid and tr, ping itin front of the plunger before 'sa' d plunger reaches the end of itsv forward stroke for cushioning the same.

Inv 'Witness whereof, I have hereunto signed my naine in the presence of -tWo subscribing witnesses.

HENRY E.. LE GENDRE.

i? Witnesses:

Enw. REDHEAD, A. B; GRovER. 

